| 摘要 |
<p>Communication is established between communication terminals arranged in different LANS while realizing dynamic response to reduction in server load, movement of communication terminal, and the like. A relay server is arranged in the LAN and can communicate with an SIP server arranged in a WAN. For instance, a first relay server exchanges account information of the communication terminals in the respective LAN with a second relay server. If exchanged account information is changed in one relay server, the account information after change is notified to the other relay server. One relay server determines the other relay server based on the exchanged account information and relays communication data between the communication terminals through the other relay server.</p> |
